Flexible vitreous coating for metals



Oct. 13, 1931. H c. MILLIGAN 1,827,536

FLEXIBLE VITREOUS COATING FR METALS Filed Jan. 16, 1930 2 Sheets-Sheet l gmc/nto y H Y Milligan,

- Oct. 13, 11931'. H Q M|LL|GAN l 1,827,536

\ FLEXIBLE VTREOUS COATING FOR IETALSv Filed Jan. 16 1930 2 Sheets-Sheet 2 H C. /l'llgan vPatented oet-13,1931

HENRY BILLIG, l' CANTON, OHIO r v'rranous comme ron. marne Application led January 16, 1930. Serial No. 421,188.

The invention relates to the coating of metal, especially iron or steel sheet metal, and more particularly to a flexible vitreous coating for sheet metal used for various Il building purposes.

The object of the invention is to provide metal sheets for exterior building purposes having a non-oxidizable,4 flexible vitreous coating entirely covering all surfaces of the sheet metal and fused or welded to the surface and into the pores of the metal; and to provide means for attaching the metal sheets to the frame structure of a building without exposing any unprotected portions of the metalto the elements.

An embodiment of the invention as applied to corrugated metal sheets for building purposes is illustrated in the accompanying drawings, in which n Figure 1 is a perspective view of one of the improved corrugated sheets provided withl apertures to receive nails or thev like for `attaching to the frame structure of a building;

Fig. 2, a similar view 'showing attaching cleats welded to the inner surface of the sheet and arranged to be coated with the nonoxidizable vitreous coating;

Fig. 3, an enlarged sectional view on the line 3--3, Fig. 2;

Fig. 4, a detached perspective view of one c of the attaching cleats, and

Fig. 5, an enlarged fragmentary sectional view through a portion of the sheet showing the vitreous coating welded or fused into the pores thereof.

Similar numerals refer to similar parts throughout the drawings.

Although the invention is adapted to the coatingof any kind of sheet metal building material in order to provide' a flexible nonoxidizable surface thereon, thel accompanying drawings illustrate the invention as ap.- plied to corrugated metal sheets.

In Fig. 1 is shown a corrugated-metal sheet 1 provided at its edge -portions with apertures 2, to receive nails or the like for attaching the sheet to the. frame structure of a building. 5 All surfaces of this sheet are arranged to be covered with the vitreous coating to be hereinafter described, the coating being a plled after the apertures 2 are formed in t e sheet in order that there will be no ex osed portions of the metal when the sheet is p aced 1n use.

In Fig. 2, the sheet 1a is similar to the sheet shown 1n Fig. 1, the nail apertures being omitted and attachingv cleats, referabl of channel form as illustrated at lbeing welded to the rear surface of the sheet near each end thereof, bridging certain of the corrugations as shown.

After these. attaching cleats have been welded to the sheet, all surfaces of the sheet and cleats are then covered with the improved vitreous coating in the manner hereinafter described.

Wires or any suitable form of clips may .be engaged withv the cleats 3 for attaching 7 the sheet to a building structure. A sheet metal article is thus produced, all surfaces of which are covered with a exible nonoxidizable vitreous coating which is weldedA or fused to the metal and will not be affected by weather conditions or hard usage.

Before the silicate or alkali coating is applied to the surface of an iron or steel sheet, all scale and oxidation is removed therefrom as by immersin it ina pickling solution in usual and well own manner; but for the purpose of the present invention, a certain amount of iron sulphide is added to the pickling solution to prevent the formation of jumpers which result from a fish scaling of the coating on the metal.

The iron sul hide treatment may be accom lished in t e usual period required for picking, which may be from three to ive minutes, depending upon the character of the iron or steel, and upon the amount of oxidation or scale to be removed therefrom.

A pickling solution containing 21% of sulphuric acid may be used, and when a pickling tank containing 400 gallons of the pickling solution is used, it has been found desirable, if not necessary, to initially add thereto some 2 pounds and 4 ounces of dry lump iron sulphide, and to add the same amount .of iron sulphide thereto every two hours durlng the time the pickling solutien-is in use; and after the solution has been used a week, it is preferred to replace the entire contents of the tank with a new solution.

v ing which causes what is known as jumpers in the enameling art.

Without the use of iron sulphide in the pickling solution, it is absolutely impossible to make an elastic enamel coated sheet metal whichwill not chipoif or fish scale, so as to form the jumpers in or on the surface ofthe metal.

In producing the vitreous coating to which the invention pertains, the metals-to be used in the coating are first converted to oxides ysuch as antimonydead, arsenic. nickel, manganese, cobalt and the like. Although these metals are given as examples, it should vbe understood that the invention is not limited to these particular metals. but other suitable metals, whose oxides will fuse at a low degree of amperaturenvith suitable iiuxes, may be use A given amount of any one or more of the metal oxides is added to a mixture containing.

boracic acid, sodium oxide, and iuoride, such as cryolite and/or iuor spar, silica, quartz, or other silicate and alumina.

The exact proportions of the several ingredients mav vary as desired as follows: Y 10% to 20% in weight of boracic acid.

5% to 20% in weight of sodium oxide.

5% to 20% of iuoride.

30% to 50% of silicate.

5% to 10% in weight of alumina.

There is added to a certain weight of these` compounds, something less than an equal amountin weight of any one or more of the metal oxides. This mass is thoroughly mixed and then put into a 'smelter where it is thoroughly fused, allowing the volatilematters to pass olf.

The fused mass is then poured into water, splintering the mass into condition for grinding. The splintered mass is then ground to an almost impalpable powder to which is added a small amount of borax, soda, litharge or such other fluxes as are-commonly used for bracing purposes. which may vary from one-half percent to two percentV in accordance with the desired hardness or resisting` qualities.

The powdered mass is then mixed with Water to the proper consistency for dipping or spraying under pressure .and the4 sheets having been pickled and treated with iron sulphide in the manner described are then coated with the metal oxide and silicate mixture, and permitted to d The coated sheets are t en submitted to a high temperature which may be approximately 2000 F. and the coated sheets are held at this temperature until the coating has thoroughly fused and the coating and the sheets are welded together, the time required for fusing and welding depending upon the -thickness and size of the metal sheets being treated, ranging from two minutes upward,

During this heating of the coated sheets the coating is fused into thev pores of the metal and welded tothe surface thereof. A non-oxidizable, flexible, vitreous coating is thus fused to all surfaces of the sheet metal, permitting the metal to be iexed or bent Without damaging the coating and providing a rust-resisting covering upon all portions4 of the metal sheet.

- The coating being iexiblewill not chip or spawl from the sheets to expose the metal surfaces thereof and mayr be attached to the frame structure of a building without leaving any exposed portions of the metal.

I claim:

1. The method of coating steel and iron sheets with enamel which consists in cleaning the surfaces of the sheets with pickling solution containing iron sulphide, coating the sheets with metal oxides and silicates, and then submitting the coated sheets to a high temperature to thoroughly fuse the coating and weld it upon the sheets.

2. The method of coating steel and iron sheets with enamel which consists in clearing the surfaces of the sheets with sulphuric acid solution containing iron sulphide. coating the sheets with metal oxides and silicates, and then submitting the coated sheets to a high temperature to thoroughly fuse the coating and Weld it upon the sheets.

3. The method of coating steel and iron sheets with enamel which consists in cleaning the surfaces of the sheets with pickling solution containing` two pounds and four ounces of iron sulphide in 400 gallons of solution, coating the sheets with metal oxides and silicates. and then submitting the coated sheets to a high temperature to thoroughly fuse the coating and weld it upon the sheets. 4. The method of coating steel and iron sheets with enamel which consists in cleaning the surfaces of the sheets with pickling solution containing two pounds and four ounces of iron sulphide in 400 gallons of solution, adding two pounds, and four lounces of iron sulphide to the solution bi-hourly, coating the sheets withmetal oxides and silicates, and then submitting the coated sheets to a high temperature to, thoroughly fuse the coating 'and weld it upon the sheets.

5. In a method of-coating steel and iron sheets, the step of cleaning the surface on th'e sheets with a pickling solution containing a metal sulphid 6. In a method of coating steel and iron sheets with enamel, the step of pickling the sheets in a sulphuric acid bath containing a metal sulphide.

7. In a method of coating steel and iron sheets with enamel, the step of treat'n the sheets which consists in prearing a sulp uric m acid pickling solution, ad ing a metal sulphide to the solution, and immersing the sheets in the solution.

8. In a method of coating steel and iron sheets with enamel, the step of treatin the sheets which consists in preparing sulp uric acid pickling solution, adding iron sulphide to the solution and immersing the sheets in the solution.

In testimony that I claim the above, I have hereunto subscribed my name.

HENRY C. MILLIGAN. 

